> pkg-config --cflags gtest
-DGTEST_HAS_PTHREAD=1 -lpthread -I/usr/lib64/pkgconfig/../../include

The `-I` is changed to `-isystem` by a downstream build system (Google Ninja)

When calling g++-13 with this flag on a file which includes `<cstdlib>`, i'm
getting a confusing build error:

In file included from ../../v8/include/v8.h:21,
                 from ../../third_party/electron_node/src/node.h:79,
                 from
../../third_party/electron_node/src/api/async_resource.cc:1:
/usr/include/c++/13/cstdlib:79:15: fatal error: stdlib.h: No such file or
directory
   79 | #include_next <stdlib.h>
      |               ^~~~~~~~~~

This is gtest-1.10.0-1.10.x86_64
The problem happens on both 15.5 and 15.6, does not happen on Tumbleweed.